If the petition is found to be sufficient, the city clerk shall so certify to the council at its next meeting, stating the number of petitioners and the percentage of the total number of voters which they constitute, and the council shall at once read the ordinance and refer it to an appropriate committee, which may be a committee of the whole. The committee or council shall thereupon provide for public hearings upon the ordinance, after the holding of which the ordinance shall be finally acted upon by the council not later than sixty-five (65) days after the date upon which it was submitted to the council by the city clerk. If the council fails to pass the proposed ordinance, or passes it in a form different from that set forth in the petition and unsatisfactory to the petitioners, the proposed ordinance shall be submitted by the council to the vote of the electors at the next regular municipal election; but if the number of signers of the petition is equal to at least twenty-five per cent (25%) of the total number of voters voting in the municipality at the last preceding presidential year general election, the council shall call a special election upon the measure. Such special election shall be held not less than thirty (30) nor more than forty-five (45) days from date of final action on the ordinance by the council or after the expiration of sixty-five (65) days from the date of submission to the council when there has been no final action; but if a regular election is to occur within three months, the council may submit the ordinance at that election. If the council passes the proposed ordinance with amendments and at least four-fifths (4/5) of the committee of petitioners do not express their dissatisfaction with such amended form by a statement filed with the city clerk within ten (10) days of the passage thereof by the council, the ordinance need not be submitted to the electors.